1. Field of the Invention
The present invention relates to an apparatus for producing a waste compressed solid.
2. Description of the Related Art
As an apparatus for compressing and solidifying a waste such as a metal chip or the like, a structure disclosed in Japanese Patent Application Laid-Open No. 9-239593 is known.
The waste compressing and solidifying apparatus mentioned above is based on a main body frame, and comprises a hopper capable of receiving a waste in the main body frame. A large-scaled supply opening portion is provided in an upper side of the hopper, and a discharge port is provided in a bottom side of the hopper. Further, a compression box provided with a compression chamber capable of being communicated with the discharge port, and a compressing means for compressing and solidifying the waste fed the compression chamber under a sealed state are provided in the main body frame. In order to feed the waste from the hopper to the compression chamber, a feed screw conveyor is provided inside the hopper so as to be capable of rotating, and the feed screw conveyor is structured such as to extend to a portion near the compression chamber.
The waste supplied into the hopper is fed to the discharge port of the hopper due to a rotation of the feed screw conveyor, and is transferred to the compression chamber. Further, the waste is made into the compressed solid in the sealed state due to an operation of the compressing means.
A filament-like waste such as the metal chip often coils around a screw shaft due to the rotation of the feed screw conveyor. In this state, when the feed screw conveyor further rotates, a lump of the coiling waste gradually grows so as to stay near the discharge port and it is necessary to interrupt the operation.
The present invention provides an apparatus for continuously producing a waste compressed solid without the waste staying in a hopper.
An apparatus for producing a waste compressed solid according to a first aspect of the present invention comprises a hopper comprising an opening for receiving a waste in an upper side thereof and a discharge port in a bottom side, a feed screw conveyor for transferring the waste to the hopper to the discharge port, and a compression chamber connected to the discharge port of the hopper and comprising a compressing means. The waste received by the hopper is carried to a side of the discharge port of the hopper by the feed screw conveyor, and is fed to the compression chamber. Next, the waste in the compression chamber is compressed and solidified by moving a piston. Accordingly, it is possible to produce a waste compressed solid from the waste. A shaft of the feed screw conveyor is formed in a taper shape so as to become gradually narrow from a base end side toward a front-end side. Accordingly, when the lump of the waste is fed to the feed screw conveyor, a twist of the waste with the shaft is gradually loosened and the waste is easily removed by itself.
According to a second aspect of the present invention, the apparatus for producing the waste compressed solid as mentioned above further comprises a control means for controlling a driving direction of the feed screw conveyer so that the feed screw conveyor can be alternately driven in both directions comprising a forward direction and a backward direction. Since the lump of the waste coiling around the feed screw conveyor is removed by alternately driving the screw conveyor in the forward direction and the backward direction, it is possible to continuously compress and solidify the waste without interrupting the operation.
According to a third aspect of the present invention, the apparatus for producing the waste compressed solid as mentioned above further comprises draw screw conveyors comprising a pair of spiral-shaped draw blades in the hopper so as to cross to the feed screw conveyor and be symmetrical with respect to the feed screw conveyor, wherein the draw blades draw the waste to the hopper in a direction of the feed screw conveyor. The draw blades of the draw screw conveyors are formed in a spiral shape wound around in both sides of the feed screw conveyor, wherein directions of the respective draw blades are directed opposite to each other, and can draw the waste to the side of the discharge port from both sides when rotated. A draw motor control unit is controlled so as to stop the draw screw conveyors or reverse rotate the draw screw conveyors at a time of rotating the feed screw conveyor in an opposite direction. Accordingly, it is possible to prevent the waste from clogging near the discharge port and it is possible to continuously compress and solidify the waste.
According to a fourth aspect of the present invention, the apparatus for producing the waste compressed solid as mentioned above further comprises first and second screw conveyors comprising spiral-shaped draw blades substantially vertical to the feed screw conveyor and substantially in symmetrical therewith, and first and second draw motors driving them respectively. It is possible to draw the waste to the side of the discharge port from both sides by driving a pair of draw screw conveyors by the respective draw motors. Further, according to this structure, since the shafts of the respective draw screw conveyors do not hang over the shaft of the feed screw conveyor, it is possible to prevent the lump of the waste coiling around the shaft of the feed screw conveyor from being caught on the respective draw screw conveyors. Further, the respective motor control units are controlled so that rotational speeds of the first and second draw screw conveyors are different from each other. A compelling force in a twisting direction is applied to the drawn waste by applying a difference to the rotational speeds of the draw screw conveyors, whereby it is possible to prevent the waste from floating up.
According to a fifth aspect of the present invention, the structure of the apparatus for producing the waste compressed solid is made as mentioned above, and further, a feed blade of the feed screw conveyor has substantially no length in a base portion of the feed screw conveyor and become gradually longer toward a direction of an end portion. Even when the waste received by the hopper is fine and much, it is hard that the waste is caught on the feed blade.
According to a sixth aspect of the present invention, the structure of the apparatus for producing the waste compressed solid is made as mentioned above, and further, a pitch of the feed blade in the feed screw conveyor becomes gradually narrower toward the side of the discharge port of the hopper, and gradually wider toward the side of the discharge port near the discharge port of the hopper. According to this structure, it is possible to slow the feed speed of the waste in the side of the discharge port rather than the side of the base end of the feed screw conveyor, and it is possible to make it faster near the discharge port. According to this structure, it becomes hard that the lump of the waste is caught on near the discharge port, and it is possible to continuously operate the apparatus for producing the waste compressed solid.